Background: Acne vulgaris is known as a commonly-seen skin disease with a considerable impact on the quality of life. At present, there have been a growing number of epidemiological, medical, demographic and sociological researches focusing on various influencing factors in the occurrence of acne. Nevertheless, the correlation between environmental factors and acne has yet to be fully investigated. Objective: To assess the impacts of individual, natural and social environmental factors on acne and to construct a framework for the potential impact of built environment on acne. Methods: A thorough review was conducted into the published social demographical, epidemiological, and environmental studies on acne through PubMed, Google Scholar and Web of Science, with reference made to the relevant literature. Results: The influencing factors in acne are classed into four major categories. The first one includes individual socioeconomic and biological factors, for example, gender, age, economic level, heredity, obesity, skin type, menstrual cycle (for females), diet, smoking, cosmetics products, electronic products, sleep quality and psychological factors. The second one includes such natural environmental factors as temperature, humidity, sun exposure, air pollution and chloracne. The third one relates to social environment, including social network and social media. The last one includes built environmental factors, for example, population density, food stores, green spaces, as well as other built environment characteristics for transport. Acne can be affected negatively by family history, overweight, obesity, oily or mixed skin, irregular menstrual cycles, sugary food, greasy food, dairy products, smoking, the improper use of cosmetics, the long-term use of electronics, the poor quality of sleep, stress, high temperature, sun exposure, air pollution, mineral oils and halogenated hydrocarbons. Apart from that, there are also potential links between built environment and acne. Yang et al. Acne Conclusions: It is necessary to determine the correlation between the built environment and acne based on the understanding of the impact of traditional factors (sociology of population and environment) on acne gained by multidisciplinary research teams. Moreover, more empirical studies are required to reveal the specific relationship between built environment and acne.

BackgroundLactic acid sting test (LAST) is a classical method to identify sensitive skin. However, some subjects with self‐perceived sensitive skin are negative for LAST.ObjectiveTo determine whether LAST scores are associated with specific phenotype of sensitive skin.MethodsA total of 292 subjects with self‐perceived sensitive skin were enrolled in this study. The Sensitive Scale was used to evaluate the severity of burning, stinging, itching, tautness, erythema and scaling based on 0–10 scale scores. In addition to the assessment of LAST scores, epidermal biophysical properties were measured using an MPA system.ResultsThe Sensitive Scale scores of stinging, itching, tautness and scaling were significantly different between the LAST‐positive and ‐negative groups. However, burning and erythema scores did not differ between the LAST‐positive and ‐negative groups. LAST scores were positively correlated with the Sensitive Scale scores for stinging, itching, tautness and scaling, but not for burning and erythema scores. Moreover, LAST scores negatively correlated with stratum corneum hydration, but positively with transepidermal water loss (TEWL) rates.ConclusionsLactic acid sting test scores positively correlated with TEWL rates. LAST scores could be used to identify subjects with sensitive skin characterized mainly by stinging and itching, but not those mainly by burning and erythema.

The skin is the largest organ of the human body, covering an area of approximately 2 m 2 in adult. The skin functions as multiple barriers, such as permeability barrier, microbial barrier, and immune barrier, protecting the skin against various insults. Among these barriers, epidermal permeability barrier prevents substances in and out the body through the skin, while melanin serves as epidermal pigment barrier, protecting the skin from excessive ultraviolet (UV) radiation. 1 Recent studies demonstrated that epidermal permeability barrier and pigment barrier co-regulated each other. Disruption of permeability

This study provides evidence that the development of life-long health behaviors that contribute to BMI are significantly influenced by parents' behaviors and parenting styles. Moreover, an interaction of parental characteristics and cultural norms is indicated.